1. Field of the Invention
This invention relates generally to post and tree pullers and, more particularly, to a hydraulic puller apparatus for extracting fence posts, small trees, tent stakes, grounding rods, mailbox posts, sign posts, and the like, including such objects that may be anchored in a concrete slug.
2. Background Art
Devices for removing fence posts, poles, tent stakes, trees, ground rods, signposts, etc. are well known in the art. Typically, fence posts, poles, tent stakes, trees, ground rods, signposts, etc., are either hammered into the ground or set in concrete thus making removal difficult and time-consuming. Some posts will be found to have broken off near ground level due to rot, high wind, fallen trees, auto mishaps or some other cause. This presents a special removal problem. Another problem occurs when a post being removed slips out of its concrete slug while it is still in the ground. Various removal devices and methods have been implemented to solve these problems.
Most prior art removal devices use a chain wrapped around the object to be removed, together with a lever and fulcrum, complex hydraulic systems, come-alongs, winches, etc. Shovels, sledgehammers, and pry bars, as well as backhoes, tractors, and small skid steer tractors are also often used to remove these types of objects.
Although some of these devices have plenty of power, they are hardly practical to use in a residential setting. Not only would the noise and torn up landscape be objectionable, but they simply would not pass through the average walk-gate opening. Most people would prefer not to have a backhoe in the flowerbed. Thus, there exists a need for a simple, quiet, powerful, portable device that will quickly pull an object out of the ground with minimal effort.
There are several patents that disclose jack-type devices of various constructions for extracting fence posts and the like from the ground.
Burke et al, U.S. Pat. No. 3,317,185 discloses an apparatus for pulling stakes, posts and the like out of the ground. The apparatus has two elongated hydraulic cylinders members mounted in parallel relation and connected to each other on opposites sides of the object to be pulled. The cylinders have a ball and socket base that rests on the ground. A pair of opposed facing clamps connected to levers grip the object and have a free end connected to draw cables that pass over pulleys connected to the piston rods of the cylinders.
Price, U.S. Pat. No. 5,794,918 discloses an apparatus and method for pulling fence posts having a fulcrum stand with an action lever hingedly connected to one end and a receiving box for encompassing the object to be moved connected to the action lever. An action handle is attached to the receiving box and the fulcrum stand, and a moveable gripping pawl having an engagement edge and a non-engagement edge is connected to the action handle for engaging the object to be pulled as the action handle is raised. The fulcrum stand and the action handle are on opposite sides of the post to prevent bending of the posts as they are pulled.
Ultimo, Sr., et al, U.S. Pat. No. 6,302,380 discloses a portable injection-casing extractor tool that facilitates soil stabilization applications that utilize compaction grouting. The casing extraction tool has dual hydraulic cylinders that provide a lifting force capable of pulling sections of grout injection casing out of the ground at an operator-controlled rate. The dual cylinders are supported on a heavy-duty base plate and chassis and are powered by a remote hydraulic power unit or “mule”. The base plate and chuck have aligned, open-face slots for positioning of the tool on installed casings and to utilize the casings for lateral support. The cylinders have an attached toothed progressive chuck mechanism that engage the injection casing at the beginning of a lifting stage and release it at the end of a lifting stage. The teeth of the progressive chuck are maintained generally flush to the casing wall during gripping and extraction steps to avoid gouging, denting and crushing movements that would damage the casings.
Salman, U.S. Pat. No. 6,398,188 discloses a post puller having an H-shaped base including a pair of parallel legs and a crossbeam normal to the legs, the crossbeam being offset from the midpoint of the legs and defining a shallow channel and a deep channel. A pair of rectangular blocks attached to the legs and crossbeam in the deep channel provides platforms on which a pair of single action hydraulic cylinders are mounted, and define a recess that straddles the post to be pulled. A cross member is pivotally mounted to each cylinder rod. A chain is suspended from the midpoint of the cross member. The chain may be wrapped directly around the post, or a post gripping structure may be attached to the free end of the chain. A pair of wheels may be mounted to the base for portability.
Pignato, U.S. Pat. No. 6,655,875 discloses a pier adjusting mechanism and method for facilitating the adjusting and leveling of a pier platform relative to a pier structure, the pier structure including at least a first post. The method includes the step of providing a platform height adjustment apparatus, the platform height adjustment apparatus including a platform support member and a height positioning mechanism. The platform height adjustment apparatus is slidably mounted on the first post. The post position of the platform height adjustment apparatus is fixed relative to the first post, the post position being situated above and proximate the pier platform. The platform support member is moved into a platform supporting position relative to the platform and the height positioning mechanism is actuated to lower or lift the pier platform.
Tyson, U.S. Pat. No. 6,527,250 discloses a device for pulling a planted post from the ground that includes a movably disposable base which is capable of disposal at least partially circumferentially about the planted post, a diametrically adjustable chain and hook gripping member connected to the base for securely gripping about the post, and a jack connected to the gripping member for mechanically displacing the gripping member and in turn the fence post from the ground.
Puff et al, U.S. Pat. No. 6,598,856 discloses a portable hydraulic stake puller that includes a hydraulic cylinder which extends to raise a jaw assembly. The jaw assembly pivots, while being raised, to grab and trap the stake. A grab hook may alternatively extract similar items not readily removable with the jaw assembly. The jaw or chain tension is controllably released when the control lever is released at any height of the stroke. Squeezing the control lever can again attain grip easily. The gripping action of the jaw is attained by at least friction against the jaw. When the control lever is released, the entire lift assembly returns to the neutral position under a spring tension. The hydraulic stake puller is mounted on wheels and controlled via handles allowing easy maneuvering.
The present invention is distinguished over the prior art in general, and these patents in particular by a hydraulic puller apparatus for extracting objects such as posts, small trees, stakes, rods, and the like, from the ground, including such objects that may be anchored in a concrete slug. The apparatus includes a pair of hydraulic jack members, each having an extensible and retractable ram member with an elongate lift arm pivotally connected at an upper end thereto and a outwardly extending horizontal tongue member at a lower end thereof. A puller head assembly is removably supported at opposed ends on the horizontal tongue members and has a pair of generally rectangular jaw support platforms disposed in parallel laterally spaced relation defining a central generally U-shaped opening therebetween which is open on one side and sized to straddle the width of the object to be extracted. A jaw member is slidably mounted on each jaw support platform in opposed facing relation for movement between a retracted position away from the U-shaped opening and an extended gripping position engaged on the object to be extracted, and each has a generally rectangular transverse grip portion configured to grip opposite sides of the object to be extracted. A drive screw member is threadedly engaged on each jaw support platform in opposed facing relation and has an inner facing end engaged with the respective jaw member for moving it between said retracted and extended positions upon rotation thereof, and each has an outer facing end configured to receive rotating means for rotating it.
To extract the object, the puller head is positioned with its U-shaped opening straddling a lower end of the object, the drive screws are rotated to move the jaws to their extended gripping position firmly engaged on opposite sides of the object, the jack members are placed on opposite sides of the object, and the lift arm tongue members are engaged in opposed ends of the jaw support platforms. The jacking mechanisms of the jack members are then actuated, preferably simultaneously, to extend the ram members to a height sufficient to extract the object from the ground.